The present invention relates to cannula sealing apparatus and methods of using cannula sealing apparatus. The present invention is particularly suited to such apparatus where surgical instruments of different sizes are required to be sealed with the same cannula sealing apparatus.
U.S. Pat. No. 5,512,053 describes a surgical cannula with a slidable reducer assembly to sealingly accommodate surgical instruments. The reducer assembly consists of multiple apertures having varying diameters such that the assembly can slide to selectively accommodate the exterior of surgical instruments having a variety of outer diameters.
U.S. Pat. No. 5,843,040 discloses a surgical sleeve that includes a housing having an opening through which surgical instruments are introduced into the surgical sleeve. A sleeve portion extends from the housing and has an inner diameter coaxial with the opening in the housing. A reducer assembly is removably secured to the housing and includes a rigid seal for rotation in a plane transverse to the sleeve portion. A resilient, laminar seal layer is generally coextensive with the seal disc and is disposed between the disc and the housing to sealingly engage a portion of the housing. A plurality of apertures are formed in the seal disc and seal layer and have varying diameters to define seals that are selectively movable, by rotation of the seal disc, over the opening in the housing to seal against exteriors of instruments disposed in the sleeve.
U.S. Pat. No. 5,201,714 provides a cannula for laparoscopic surgery wherein the cannula comprises a housing and an elongated tube with a passageway formed within the housing so that laparoscopic instruments may be passed through the housing and the elongated hollow tube into the abdominal cavity of a patient. A pair of rollers are mounted within the housing, the rollers being spring-urged together to close the passageway through the housing when an instrument is withdrawn. A slidable plate having apertures of different sizes are mounted in the housing with the apertures provided with slitted seals therein to close the passageway through the housing. The varying sized apertures in the slidable plate permit laparoscopic instruments of varying diameters to be used and to maintain an effective seal around the instrument.
WO 94 017 844 discloses a seal for use with a surgical instrument to provide a gas tight seal with the instrument having a diameter within a wide range of diameters. The seal comprises a seal body, an instrument seal, and a laterally compliant seal mounting. The seal body includes a bore through which the instrument is passed. The instrument seal extends radially outwards from an instrument port formed in the instrument seal through which the instrument is passed, and also extends axially from the instrument port in the direction opposite to that in which the instrument is passed through the instrument port. The laterally compliant seal mounting mounts the instrument seal to the seal body, forms a gas tight seal between the instrument seal and the seal body, and allows the instrument seal to move freely laterally in response to lateral movement of the instrument.
U.S. Pat. No. 5,607,397 and U.S. Pat. No. 5,569,206 disclose adaptors that can be attached around the cannula handle. The adaptors include a smaller seal that projects to one side of the handle and which can be pivoted over the handle about an axis perpendicular to the elongate axis of the cannula and to one side of that axis.
It is an object of the present invention to attempt to overcome at least one of the problems associated with the above publications or other problems.